1. Field of the Invention
This invention relates to a printing paper protecting device which is capable of preventing the printing surface of printing paper, such as sublimation type printing paper, from being soiled during transportation or loading into a paper cassette.
2. Description of the Related Art
FIG. 16 is a perspective view illustrating an example of how a stack of conventional printing paper is packaged. In FIG. 16, a paper stack 1, consisting of sheets of sublimation type printing paper (image-receiving paper), is loosely packaged by a first packaging material 2. In other words, the first packaging material 2 is larger than the paper. The first packaging material 2 has a notch 2a and opening perforations 2b.
FIG. 17 is a perspective view illustrating another example of how a stack of conventional sublimation type printing paper is packaged. In FIG. 17, the paper stack 1 is closely packaged by a second packaging material 3. The second packaging material 3 has an opening ribbon 3a.
FIG. 18 is a plan view illustrating an example of a paper cassette for a printer. In FIG. 18, a side wall surface of a cassette body 4 is provided with positioning protrusions 4a which make contact with the rear end portion and two side surface portions of the printing paper. A pair of separating claws 5 are mounted in the cassette body 4 at positions where they make contact with the two corners of the forward end portion of the printing paper. The separating claws 5 separate the printing paper one by one when the paper is fed. Also, a pressure plate 6 on which the printing paper is placed is provided inside the cassette body 4. Springs 7 are provided between the cassette body 4 and the pressure plate 6 to urge the pressure plate 6 in the upward direction.
How the paper stack 1 is set in the paper cassette will be explained. In the case of the paper stack 1 packaged by the first packaging material 2 shown in FIG. 16, first, the first packaging material 2 is unsealed from the notch 2a along the perforations 2b. Next, the forward end portion of the paper stack 1 is placed in the cassette body 4 at a predetermined position with the paper stack 1 being held by hand in the remaining portion of the first packaging material 2, as shown in FIG. 19. Thereafter, the remaining portion of the first packaging material 2 is pulled out in the direction indicated by an arrow in FIG. 19.
In the case of the paper stack 1 packaged by the second packaging material 3 shown in FIG. 17, since the paper stack 1 is closely packaged by the packaging material 3, it is difficult to pull out the second packaging material 3 in the manner shown in FIG. 19. Hence, after the unsealing ribbon 3a is removed, the whole of the second packaging material 3 is peeled off the paper stack 1. Then, the paper stack 1 is placed in the cassette body 4 at a predetermined position with the paper stack 1 being directly held by hand, as shown in FIG. 20.
The paper cassette with the paper stack 1 set therein is loaded in a printer body 8, as shown in FIG. 21.
In the case of the conventional paper stack which is packaged by the first packaging material 2 shown in FIG. 16, since the paper stack 2 is loosely packaged, the end portion of the paper stack 1 may become irregular due to vibrations which occur during transportation or the like. To square the ends of the paper stack 1, the paper stack 1 must be handled by hand, making the printing surface (the dyeing surface) of the printing paper soiled by fats in fingerprints or the like. In the case of the conventional paper stack packaged by the second packaging material shown in FIG. 17, since the paper stack 1 is closely packaged, the corner portions of the second packaging material 3 may be damaged, thus damaging the printing paper. Furthermore, the paper stack 1 must be handled directly by hand, and this makes the printing surface of the printing paper soiled. Printing cannot be completely done on the printing paper whose printing surface is partially soiled. Consequently, the printing paper is wasted, and the printing quality deteriorates.